If you already own a Delica or Endura, you have one of the bestselling knives Spyderco makes. These models are a bit different from the normal C10 Endura4 and C11 Delica 4 Lightweights. They are in a range of handle colors with full-flat ground blades. Their FRN (fiberglass reinforced nylon) handles come in vibrant tones including blue, green, brown, gray and purple. Molded onto the handle's surface is Bi-Directional Texturing for slip-free tactile traction. Inside the handle are dual skeletonized stainless steel liners which strengthen the knife without additional weight and double as an anchor for external and internal components to attach through generating more sturdiness and rigidity. The blades are full flat-ground VG-10 with a thinner highly refined cutting edge and a larger 13mm opening hole. Added to the blade's spine is slip resistant jimping. Phosphor bronze washers smooth out the open/close action and the clip is upgraded to a four-way tip-up, tip-down, left- or right-handed clip. Flat-ground Endura and Delica Lightweights are produced in limited numbers as part of the 2010 production line up.